Battery and battery laminate

Abstract

The invention relates to a battery and a battery laminate. The plurality of first current collector parts (112a) are led out from the laminated part (100a). The exterior material (200) covers the battery element (100). The first tab (310) is connected to the plurality of first collector parts (112a). The plurality of first current collector parts (112a) between the laminated part (100a) and the first tab (310) have a first region (RG1). In the first region (RG1), the thickness in the third direction (Z) of a bundle including the plurality of first current collector sections (112a) decreases from the laminated section (100a) to the first tab (310), and the rate of decrease in the thickness decreases from the laminated section (100a) to the first tab (310).

Description

[0001] This application is a divisional application: the application number of the parent application is "202180012690.0", and the name of the invention is "Battery and method for manufacturing a battery". Technical Field

[0002] The present invention relates to a battery and a battery stack. Background Art

[0003] In recent years, non-aqueous electrolyte secondary batteries, especially lithium-ion secondary batteries, have been developed. Lithium-ion secondary batteries have a battery element having a positive electrode, a negative electrode and a separator. The positive electrode, the negative electrode and the separator form a laminated portion of the battery element. The lithium-ion secondary battery also has an outer packaging material that wraps the battery element. A positive electrode collector foil and a negative electrode collector foil are respectively drawn out from the positive electrode and the negative electrode of the laminated portion of the battery element. The positive electrode collector foil and the negative electrode collector foil are respectively connected to the positive electrode tab and the negative electrode tab.

[0004] For example, a plurality of battery elements each wrapped in an outer packaging material may be stacked, as described in Patent Document 1. Patent Document 1 describes that each tab (positive electrode tab or negative electrode tab) drawn out from the outer packaging material is bent to bundle the plurality of tabs.

[0005] Patent Document 2 describes bending the outer packaging material together with the tab toward the battery element. Patent Document 2 describes that by bending the outer packaging material together with the tab, the length of the outer packaging material in the direction of leading out the tab can be shortened compared to the case where the outer packaging material is not bent, thereby increasing the volume energy density.

[0006] Patent Document 3 describes that by forming cutouts on both sides of a tab in an exterior material, the tab can be easily bent together with the exterior material.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2016 / 020999

[0010] Patent Document 2: Japanese Patent Application Laid-Open No. 11-260327

[0011] Patent Document 3: International Publication No. 2019 / 150904 Summary of the invention

[0012] Problems to be solved by the invention

[0013] In order to shorten the length of the tab for the tip of the tab to reach a specific position, the tab itself is sometimes not bent, but the portion between the laminated portion and the tab in the outer packaging material is bent so that the tip of the tab is directed in a specific direction. In this case, it is necessary to bend a bundle including a plurality of collector portions (positive electrode collector foil or negative electrode collector foil) drawn from the laminated portion and existing between the laminated portion and the tab. However, if the bundle is bent, there is a concern that the collector portion (collector foil) may break.

[0014] One example of the object of the present invention is to facilitate bending of a bundle including a plurality of current collector portions. Other objects of the present invention will become apparent from the description of this specification.

[0015] Solutions to Solve Problems

[0016] One embodiment of the present invention is a battery comprising:

[0017] A battery element comprising a stacked portion including a plurality of first electrodes, a plurality of second electrodes, and a plurality of separators, and a plurality of first current collector portions extending from the stacked portion;

[0018] An outer packaging material that wraps the battery element; and

[0019] a first electrode tab connected to the plurality of first current collector portions;

[0020] The plurality of first current collector portions between the stacking portion and the first electrode tab have a first region in which the thickness of a bundle including the plurality of first current collector portions decreases from the stacking portion to the first electrode tab, and a rate of reduction of the thickness decreases from the stacking portion to the first electrode tab.

[0021] Another aspect of the present invention is a battery stack including a plurality of batteries stacked on each other.

[0022] The above-mentioned multiple batteries respectively have:

[0023] A battery element comprising a stacked portion including a plurality of first electrodes, a plurality of second electrodes, and separators between the plurality of first electrodes and the plurality of second electrodes, and a plurality of first current collector portions extending from the stacked portion;

[0024] An outer packaging material that wraps the battery element; and

[0025] a first electrode tab having a base end located on the side where the battery element is located and connected to the plurality of first current collector portions;

[0026] In each of the plurality of batteries, the plurality of first current collector portions and the outer packaging material have a bent portion bent along a fold, the fold being formed in a portion of the plurality of first current collector portions and the outer packaging material located between the stacked portion and the base end of the first electrode tab,

[0027] In each of the plurality of batteries, the base end of the first electrode tab and the leading end of the outer packaging material bent at the bent portion face the same direction.

[0028] The plurality of first tabs of the plurality of batteries are bundled together.

[0029] In each of the plurality of batteries, the plurality of first current collector portions between the stacked portion and the first tab have a first region, in which a thickness of a bundle including the plurality of first current collector portions decreases from the stacked portion to the first tab, and a rate of decrease in the thickness decreases from the stacked portion to the first tab,

[0030] In each of the plurality of batteries, the folds of the plurality of first current collector portions are located at one of the first regions of the plurality of first current collector portions and a region of the plurality of first current collector portions located on the first tab side relative to the first region.

[0031] Another embodiment of the present invention is a method for manufacturing a battery, comprising the following steps:

[0032] A plurality of first collector portions led out from a stacked portion including a plurality of first electrodes, a plurality of second electrodes and a plurality of separators are bundled toward a first pole lug, and at least a portion of the plurality of first collector portions located between the stacked portion and the first pole lug are pressed in a thickness direction of the bundle including the plurality of first collector portions, while the plurality of first collector portions are joined to the first pole lug.

[0033] The effects of the invention are as follows.

[0034] According to the above aspect of the present invention, a bundle including a plurality of current collector portions can be easily bent. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a top view of the battery according to the embodiment.

[0036] Figure 2 yes Figure 1 Right side view of the battery shown.

[0037] Figure 3 yes Figure 1 Rear view of the battery shown.

[0038] Figure 4Yes Figure 3 The area α is shown enlarged.

[0039] Figure 5 yes Figure 1 An enlarged view of the first tab of the battery and its surroundings is shown.

[0040] Figure 6 yes Figure 5 AA′ cross-sectional view.

[0041] Figure 7 It is used to illustrate Figures 1 to 6 A diagram showing an example of a method for manufacturing a battery shown in FIG.

[0042] Figure 8 It is used to illustrate Figures 1 to 6 A diagram showing an example of a method for manufacturing a battery shown in FIG.

[0043] Fig. 9 It is used to illustrate Figures 1 to 6 Schematic diagram of an example of application of the battery shown. DETAILED DESCRIPTION

[0044] Hereinafter, the embodiments of the present invention will be described using the drawings. In addition, in all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be appropriately omitted.

[0045] In this specification, unless otherwise specified, ordinal numbers such as "first", "second", and "third" are used only to distinguish structures with the same name and do not mean specific characteristics of the structures (for example, order or importance).

[0046] Figure 1 It is a top view of the battery 10 according to the embodiment. Figure 2 yes Figure 1 A right side view of battery 10 is shown. Figure 3 yes Figure 1 A rear view of the battery 10 is shown. Figure 4 Yes Figure 3 The area α is shown enlarged. Figure 5 yes Figure 1 An enlarged view of the first electrode tab 310 and its surroundings of the battery 10 is shown. Figure 6 yes Figure 5 AA′ cross-sectional view.

[0047] The battery 10 includes a battery element 100 , an exterior material 200 , a first electrode tab 310 , and a second electrode tab 320 . The battery element 100 includes a stacked portion 100 a and a plurality of first current collector portions 112 a . The stacked portion 100 a includes a plurality of first electrodes 110 , a plurality of second electrodes 120 , and a plurality of separators 130 .

[0048] Figures 1 to 6 , the first direction X is the length direction of the battery 10 (battery element 100). The positive direction of the first direction X (the direction indicated by the arrow showing the first direction X) is the direction from the second pole tab 320 toward the first pole tab 310, and is the front direction of the battery 10 (battery element 100). The negative direction of the first direction X (the opposite direction of the direction indicated by the arrow showing the first direction X) is the direction from the first pole tab 310 toward the second pole tab 320, and is the rear direction of the battery 10 (battery element 100). The second direction Y is a direction intersecting the first direction X, specifically, a direction orthogonal to the first direction X, and is the width direction of the battery 10 (battery element 100). The positive direction of the second direction Y (the direction indicated by the arrow showing the second direction Y) is the right direction of the battery 10 when the battery 10 is viewed from the positive direction of the first direction X. The negative direction of the second direction Y (the opposite direction of the direction indicated by the arrow showing the second direction Y) is the left direction of the battery 10 when the battery 10 is viewed from the positive direction of the first direction X. The third direction Z is a direction intersecting both the first direction X and the second direction Y, specifically, a direction orthogonal to both the first direction X and the second direction Y, and is a thickness (height) direction of the battery 10 (battery element 100). The positive direction of the third direction Z (the direction indicated by the arrow indicating the third direction Z) is the upward direction of the battery 10. The negative direction of the third direction Z (the opposite direction to the direction indicated by the arrow indicating the third direction Z) is the downward direction of the battery 10. In the following Figures 7 to 9 The same is true in .

[0049] Figure 5 In FIG. 1 , a fold C indicated by a dotted line shows the position of a fold formed when the exterior packaging material 200 is folded between the laminated portion 100 a and the first electrode tab 310 .

[0050] In the present embodiment, the battery 10 is a lithium ion secondary battery, but the battery 10 may be a battery other than a lithium ion secondary battery.

[0051] use Figure 6 The outline of the battery 10 will be described.

[0052] The plurality of first collector portions 112a are respectively led out from the plurality of first electrodes 110 of the stacking portion 100a toward the front of the stacking portion 100a (the positive direction of the first direction X). The outer packaging material 200 wraps the battery element 100. The first pole tab 310 is connected to the plurality of first collector portions 112a. The plurality of first collector portions 112a between the stacking portion 100a and the first pole tab 310 have a first region RG1 and a second region RG2. The first region RG1 is located near the first pole tab 310 relative to the stacking portion 100a in the first direction X. The second region RG2 is located on the stacking portion 100a side relative to the first region RG1 in the first direction X. Furthermore, the second region RG2 is located near the stacking portion 100a in the first direction X relative to the first pole tab 310.

[0053] In the first region RG1, the thickness of the bundle including the plurality of first collector portions 112a in the third direction Z (the distance in the third direction Z between two first collector portions 112a located at both ends of the plurality of first collector portions 112a in the third direction Z) decreases nonlinearly from the laminated portion 100a to the first pole tab 310 (as it moves toward the positive direction of the first direction X). Specifically, in the first region RG1, the thickness of the bundle including the plurality of first collector portions 112a in the third direction Z decreases from the laminated portion 100a to the first pole tab 310 (as it moves toward the positive direction of the first direction X), and the reduction rate of the thickness decreases from the laminated portion 100a to the first pole tab 310 (as it moves toward the positive direction of the first direction X). For example, in the first region RG1, the thickness of the bundle including the plurality of first collector portions 112a in the third direction Z can be consistent with or approximate to a function that is convex downward, with the position in the first direction X as a variable.

[0054] In the second region RG2, the thickness of the bundle including the plurality of first collector portions 112a in the third direction Z (the distance in the third direction Z between two first collector portions 112a located at both ends of the plurality of first collector portions 112a in the third direction Z) decreases nonlinearly from the laminated portion 100a to the first pole tab 310 (as it moves toward the positive direction of the first direction X). Specifically, in the second region RG2, the thickness of the bundle including the plurality of first collector portions 112a in the third direction Z decreases from the laminated portion 100a to the first pole tab 310 (as it moves toward the positive direction of the first direction X), and the reduction rate of the thickness increases from the laminated portion 100a to the first pole tab 310 (as it moves toward the positive direction of the first direction X). For example, in the second region RG2, the thickness of the bundle including the plurality of first collector portions 112a in the third direction Z can be consistent with or approximate to a function that is convex upward, with the position in the first direction X as a variable.

[0055] In the present embodiment, the thickness (in the third direction Z) of the bundle of the plurality of first current collector portions 112a in the vicinity of the first electrode tab 310 in the first region RG1 can be thinner than the thickness (in the third direction Z) of the bundle of the plurality of first current collector portions 112a in the vicinity of the first electrode tab 310 in the case where each first current collector portion 112a extends straight from the laminated portion 100a to the first electrode tab 310. In this case, even if the plurality of first current collector portions 112a are bent in the first region RG1 or in the vicinity of the first region RG1, the possibility of each first current collector portion 112a being broken is reduced compared to the case where each first current collector portion 112a extends straight from the laminated portion 100a to the first electrode tab 310. Therefore, it is easy to bend the plurality of first current collector portions 112a so that the front end (the end on the positive direction side of the first direction X) of the first electrode tab 310 faces a specific direction. For example, the first current collectors 112a and the outer packaging material 200 form a fold C ( Figure 5 ) method of bending.

[0056] The plurality of first current collector portions 112a between the stacked portion 100a and the first electrode tab 310 may further include a region located on the first electrode tab 310 side relative to the first region RG1. In this region, the minimum value of the thickness of the bundle including the plurality of first current collector portions 112a in the third direction Z (the distance in the third direction Z between two first current collector portions 112a located at both ends of the bundle in the third direction Z among the plurality of first current collector portions 112a) is, for example, 50% or more, 65% or more, 80% or more, or 95% or more of the maximum value of the thickness of the bundle including the plurality of first current collector portions 112a in the third direction Z.

[0057] The plurality of second current collector portions (not shown) and the second tabs 320 respectively led out from the plurality of second electrodes 120 toward the rear of the stacked portion 100 a (in the negative direction of the first direction X) may also have the same Figure 6 That is, the plurality of second current collector portions (not shown) may also have regions corresponding to the first region RG1 and the second region RG2 similarly to the plurality of first current collector portions 112a. Alternatively, the second current collector portion (not shown) and the second electrode tab 320 drawn out from the second electrode 120 may also have regions corresponding to the first region RG1 and the second region RG2. Figure 6 For example, the plurality of second current collector portions (not shown) may not have regions corresponding to the first region RG1 and the second region RG2.

[0058] use Figures 1 to 4 The detailed structure of the battery 10 will be described.

[0059] The first pole tab 310 is located in front of the battery 10 (in the positive direction of the first direction X), and the second pole tab 320 is located in the rear of the battery 10 (in the negative direction of the first direction X). However, the first pole tab 310 and the second pole tab 320 may also be located on a common side of the battery 10, such as in front of the battery 10 (in the positive direction of the first direction X) or in the rear (in the negative direction of the first direction X). In this case, the first pole tab 310 and the second pole tab 320 are arranged in the second direction Y, for example.

[0060] The outer packaging material 200 wraps the battery element 100 together with the electrolyte (not shown). The outer packaging material 200 has a first outer packaging material sheet 210 and a second outer packaging material sheet 220. The first outer packaging material sheet 210 covers the upper surface of the laminated portion 100a (the surface on the positive side of the third direction Z), and the second outer packaging material sheet 220 covers the lower surface of the laminated portion 100a (the surface on the negative side of the third direction Z). When viewed from the third direction Z, the first outer packaging material sheet 210 and the second outer packaging material sheet 220 are attached to each other in the area surrounding the laminated portion 100a. In addition, both sides of the second direction Y of the laminated portion 100a in the outer packaging material 200 are folded back toward the laminated portion 100a. In detail, as Figure 4 As shown, the portion of the exterior material 200 on the negative side of the second direction Y includes a portion bent from the negative direction of the second direction Y toward the positive direction of the third direction Z, and a portion folded back from the bent portion and located on the positive side of the second direction Y relative to the bent portion. However, the folded shape of the exterior material 200 is not limited to Figure 4 In addition, the portion of the outer packaging material 200 on the positive side of the second direction Y may have the same Figure 4 The same shape as shown, or may also have a shape similar to Figure 4 According to the present embodiment, compared with a case where the outer packaging material 200 is not folded back, the volume of the battery 10 can be reduced, and the volume energy density of the battery 10 can be increased.

[0061] In the present embodiment, both sides of the laminated portion 100a in the exterior material 200 in the second direction Y are folded back toward the laminated portion 100a. However, only one of the two sides of the laminated portion 100a in the exterior material 200 in the second direction Y may be folded back toward the laminated portion 100a. That is, at least one of the two sides of the laminated portion 100a in the exterior material 200 in the second direction Y may be folded back toward the laminated portion 100a.

[0062] In the present embodiment, the exterior material 200 has two exterior material sheets (a first exterior material sheet 210 and a second exterior material sheet 220). However, the exterior material 200 may also have only one exterior material sheet. In this case, the exterior material sheet may be folded back on one of the two sides in the second direction Y of the battery element 100 (laminate portion 100a) in such a manner that a portion of the exterior material sheet covers the upper surface of the laminate portion 100a (the surface on the positive direction side of the third direction Z) and another portion of the exterior material sheet covers the lower surface of the laminate portion 100a (the surface on the negative direction side of the third direction Z), so that the portion of the exterior material sheet is bonded to the other portion of the exterior material sheet.

[0063] The cutouts 202 are provided on both sides of the first electrode tab 310 in the exterior material 200 in the second direction Y. The cutouts 202 are open in the direction from the laminated portion 100a side toward the first electrode tab 310 side (the positive direction of the first direction X) and in the direction from the first electrode tab 310 toward both sides of the first electrode tab 310 in the second direction Y (the cutout 202 on the left side (the negative direction side of the second direction Y) is open in the negative direction of the second direction Y, and the cutout 202 on the right side (the positive direction side of the second direction Y) is open in the positive direction of the second direction Y). In this case, when the exterior material 200 is folded along the fold C between the laminated portion 100a and the first electrode tab 310, the cutouts 202 can be used as the starting point of the fold C of the exterior material 200. Therefore, in this embodiment, it is easier to fold the exterior material 200 between the laminated portion 100a and the first electrode tab 310 than when the cutouts 202 are not provided. Furthermore, when the cutout 202 is provided, it is not necessary to bend the folded-back portions on both sides of the second direction Y of the exterior material 200 from the positive direction of the first direction X toward the positive direction or negative direction of the third direction Z. It is difficult to bend the folded-back portions on both sides of the second direction Y of the exterior material 200 from the positive direction of the first direction X toward the positive direction or negative direction of the third direction Z. However, in the present embodiment, as described above, it is not necessary to bend the folded-back portions on both sides of the second direction Y of the exterior material 200. Therefore, in the present embodiment, it is easier to bend the exterior material 200 between the laminated portion 100a and the first electrode tab 310 than when the cutout 202 is not provided.

[0064] In the direction from the first pole tab 310 side toward the laminated portion 100a side (the negative direction of the first direction X), the edge of the notch 202 on the laminated portion 100a side is located on the first pole tab 310 side relative to the first region RG1 of the plurality of first current collector portions 112a. In this case, in the direction from the first pole tab 310 side toward the laminated portion 100a side (the negative direction of the first direction X), the distance between the edge of the notch 202 on the laminated portion 100a side and the front surface of the laminated portion 100a (the surface on the positive direction side of the first direction X) can be increased compared to the case where the edge of the notch 202 on the laminated portion 100a side is aligned with the first region RG1 of the plurality of first current collector portions 112a or is located on the laminated portion 100a side relative to the first region RG1. Therefore, it is possible to reduce the reduction in the sealing performance of the exterior material 200 due to the provision of the notch 202. However, in the direction from the first pole tab 310 side toward the stacking portion 100a side (the negative direction of the first direction X), the edge of the stacking portion 100a side in the cutout 202 can be aligned with the first region RG1 of the plurality of first collector portions 112a, or can be located on the stacking portion 100a side relative to the first region RG1.

[0065] The end of the cutout 202 on the left side (the negative direction side of the second direction Y) of the two cutouts 202 on the first pole tab 310 side is located near the end (left side surface) of the left side (the negative direction side of the second direction Y) of the laminated portion 100a in the second direction Y. In this case, the length of the fold C can be shortened compared to a case where the end of the cutout 202 on the left side (the negative direction side of the second direction Y) of the two cutouts 202 on the first pole tab 310 side is located near the end (left side surface) of the left side (the negative direction side of the second direction Y) of the laminated portion 100a in the second direction Y compared to the end (left side surface) of the left side (the negative direction side of the second direction Y) of the first pole tab 310. However, the end of the cutout 202 on the left side (negative direction side of the second direction Y) of the two cutouts 202 on the first pole tab 310 side may be located near the end (left side surface) of the left side (negative direction side of the second direction Y) of the laminated portion 100a compared to the end of the left side (negative direction side of the second direction Y) of the first pole tab 310 in the second direction Y. Alternatively, the end of the cutout 202 on the left side (negative direction side of the second direction Y) of the two cutouts 202 on the first pole tab 310 side may be located at a position equidistant from the end of the left side (negative direction side of the second direction Y) of the first pole tab 310 and the end (left side surface) of the left side (negative direction side of the second direction Y) of the laminated portion 100a in the second direction Y. In addition, the above matters are also the same for the end of the cutout 202 on the right side (positive direction side of the second direction Y) of the two cutouts 202 on the first pole tab 310 side.

[0066] The region where the cutout 202 is provided is not limited to the present embodiment. For example, the cutout 202 may be provided only on one of the two sides of the first pole tab 310 in the exterior material 200 in the second direction Y. That is, the cutout 202 may be provided on at least one of the two sides of the first pole tab 310 in the exterior material 200 in the second direction Y. Even in the case where the cutout 202 is provided only on one of the two sides of the first pole tab 310 in the exterior material 200 in the second direction Y, the exterior material 200 can be easily bent compared to the case where the cutout 202 is not provided.

[0067] The direction in which the cutout 202 opens is not limited to the present embodiment. For example, the cutout 202 may not open in the direction from the first pole tab 310 toward both sides of the second direction Y of the first pole tab 310 (the cutout 202 on the left side (the negative direction side of the second direction Y) opens in the negative direction of the second direction Y, and the cutout 202 on the right side (the positive direction side of the second direction Y) opens in the positive direction of the second direction Y), or may open only in the direction from the laminated portion 100a side toward the first pole tab 310 side (the positive direction of the first direction X). In this case, compared with the case where the cutout 202 is not provided, the exterior material 200 can be easily bent between the laminated portion 100a and the first pole tab 310.

[0068] In addition, the cutouts 202 on both sides of the second electrode tab 320 in the exterior material 200 in the second direction Y may be the same as the cutouts 202 on the first electrode tab 310 side, or may be different from the cutouts 202 on the first electrode tab 310 side. Alternatively, the cutouts 202 may not be provided on at least one of the first electrode tab 310 side and the second electrode tab 320 side.

[0069] use Figure 5 The detailed structure of the battery element 100 will be described.

[0070] The first electrode 110 and the second electrode 120 have different polarities. The first electrode 110, the first current collector 112, the first active material layer 114, the second electrode 120, the second current collector 122, and the second active material layer 124 are respectively a positive electrode, a positive electrode current collector, and a positive electrode active material layer, a negative electrode, a negative electrode current collector, and a negative electrode active material layer. However, the first electrode 110, the first current collector 112, the first active material layer 114, the second electrode 120, the second current collector 122, and the second active material layer 124 may also be respectively a negative electrode, a negative electrode current collector, and a negative electrode active material layer, a positive electrode, a positive electrode current collector, and a positive electrode active material layer.

[0071] The first electrode 110 includes a first current collector 112 and a first active material layer 114. In the present embodiment, the first active material layer 114 is located on both the upper surface (the surface on the positive direction side of the third direction Z) and the lower surface (the surface on the negative direction side of the third direction Z) of the first current collector 112. However, the first active material layer 114 may be located only on one of the upper surface and the lower surface of the first current collector 112.

[0072] The second electrode 120 includes a second current collector 122 and a second active material layer 124. In the present embodiment, the second active material layer 124 is located on both the upper surface (the surface on the positive direction side of the third direction Z) and the lower surface (the surface on the negative direction side of the third direction Z) of the second current collector 122. However, the second active material layer 124 may be located only on one of the upper surface and the lower surface of the second current collector 122.

[0073] The separator 130 is located between the first electrode 110 and the second electrode 120 adjacent to each other in the third direction Z. The separator 130 is provided to prevent the first electrode 110 and the second electrode 120 adjacent to each other in the third direction Z from contacting each other (ie, short-circuiting).

[0074] The stacked portion 100 a includes a plurality of first electrodes 110 , a second electrode 120 , and a separator 130 stacked in a third direction Z. The plurality of first electrodes 110 and the plurality of second electrodes 120 are alternately stacked in the third direction Z with the separator 130 located between adjacent first electrodes 110 and second electrodes 120 .

[0075] The first current collector portion 112a is connected to the first current collector 112 of the battery element 100. Specifically, the first current collector 112 and the first current collector portion 112a form an integrated conductive portion (conductive foil). In other words, the conductive portion (conductive foil) becomes the first current collector 112 of the first electrode 110 in the region overlapping with the second electrode 120 and the separator 130 along the third direction Z, and becomes the first current collector 112a on the outside of the laminated portion 100a (on the positive direction side of the first direction X of the laminated portion 100a). The same is true for the second current collector portion (not shown) led from the second electrode 120 toward the rear of the laminated portion 100a (in the negative direction of the first direction X).

[0076] Figure 7 and Figure 8 It is used to illustrate Figures 1 to 6 FIG. 2 is a diagram showing an example of a method for manufacturing the battery 10 shown in FIG. Figure 7 Corresponds to Figure 6 . Figure 8 Corresponds to Figure 1 .

[0077] First, the battery element 100 is formed. The battery element 100 is formed by alternately stacking a plurality of first electrodes 110 and a plurality of second electrodes 120 with separators 130 disposed between adjacent first electrodes 110 and second electrodes 120 .

[0078] Then, if Figure 7 As shown, a plurality of first current collector portions 112a are bundled to the first pole tab 310, and at least a portion of the plurality of first current collector portions 112a located between the stacking portion 100a and the first pole tab 310 are pressed in the thickness direction (third direction Z) of the bundle including the plurality of first current collector portions 112a by using a first clamp J1 and a second clamp J2, while the plurality of first current collector portions 112a are joined to the first pole tab 310.

[0079] A plurality of first current collector portions 112a are placed on the second jig J2, and the first jig J1 is pressed from above the plurality of first current collector portions 112a (in the positive direction of the third direction Z) toward below (in the negative direction of the third direction Z), thereby pressing at least a portion of the plurality of first current collector portions 112a in the thickness direction (in the third direction Z) of the bundle including the plurality of first current collector portions 112a. In this case, the portion of the plurality of first current collector portions 112a pressed in the thickness direction (in the third direction Z) may not be subjected to a joining process such as welding in a manner that does not leave the following strain. The method of pressing the plurality of first current collector portions 112a is not limited to the method of this embodiment.

[0080] The plurality of first current collector portions 112 a are joined to the first electrode tab 310 by welding such as heat welding or ultrasonic welding.

[0081] In the present embodiment, each first current collector portion 112a is joined to the first electrode tab 310 in a state where a strain (i.e., a force that applies the strain) is applied to the shape extending straight from the stacked portion 100a toward the first electrode tab 310. After the force is released (for example, after the first jig J1 and the second jig J2 are separated from the plurality of first current collector portions 112a), the strain applied to each first current collector portion 112a remains. As a result, the first region RG1 and the second region RG2 ( Figure 6 ).

[0082] A plurality of second current collector portions (not shown) respectively extending from the plurality of second electrodes 120 toward the rear of the stacked portion 100a (in the negative direction of the first direction X) can also be used with Figure 7 The second electrode tab 320 is joined in the same manner as described above.

[0083] Then, if Figure 8As shown, the upper surface of the laminated portion 100a (the surface on the positive side of the third direction Z) is covered by the first exterior material sheet 210, and the lower surface of the laminated portion 100a (the surface on the negative side of the third direction Z) is covered by the exterior material 200. Next, in the region surrounding the laminated portion 100a when viewed from the third direction Z, the first exterior material sheet 210 and the second exterior material sheet 220 are joined to each other, for example, by welding. Next, cutouts 202 (for example, Figure 1 ). Then, if Figure 4 As shown, both sides of the laminated portion 100 a in the exterior material 200 in the second direction Y are folded back toward the laminated portion 100 a.

[0084] In this way, the battery 10 is manufactured.

[0085] Fig. 9 It is used to illustrate Figures 1 to 6 Schematic diagram of an example of application of the battery 10 shown. Figure 5 and Figure 6 and use Fig. 9 An example of application of the battery 10 will be described.

[0086] In this example, the plurality of batteries 10 (battery elements 100) are stacked in the thickness direction (third direction Z) of each battery 10. The plurality of first current collector portions 112a of each battery 10 (battery element 100) and the exterior material 200 are folded along the fold line C. The first tabs 310 of each battery 10 (battery element 100) are bundled at a location located in front of each battery element 100 (on the positive direction side of the first direction X) and at the center of the plurality of batteries 10 (multiple battery elements 100) in the third direction Z.

[0087] The plurality of first current collector portions 112a and the exterior material 200 of each battery 10 (battery element 100) are bent so that the front end of the first electrode tab 310 (the end on the positive direction side of the first direction X) faces different directions relative to the direction from the stacked portion 100a toward the first electrode tab 310 (the positive direction of the first direction X). Fig. 9In the example shown, the front end (the end on the positive direction side of the first direction X) of the first electrode tab 310 of the battery 10 (battery element 100) of the first layer facing from the negative direction to the positive direction of the third direction Z faces a direction inclined at a predetermined angle from the positive direction of the first direction X to the positive direction of the third direction Z with respect to the positive direction of the first direction X. The front end (the end on the positive direction side of the first direction X) of the first electrode tab 310 of the battery 10 (battery element 100) of the second layer facing from the negative direction to the positive direction of the third direction Z faces a direction inclined at an angle smaller than the predetermined angle of the first electrode tab 310 of the battery 10 (battery element 100) of the first layer facing from the negative direction to the positive direction of the third direction Z with respect to the positive direction of the first direction X. The front end (the end on the positive direction side of the first direction X) of the first electrode tab 310 of the battery 10 (battery element 100) of the third layer facing from the negative direction to the positive direction of the third direction Z faces a direction inclined at a predetermined angle from the positive direction of the first direction X to the negative direction of the third direction Z with respect to the positive direction of the first direction X. The front end (the end on the positive direction side of the first direction X) of the first electrode tab 310 of the fourth layer battery 10 (battery element 100) that faces from the negative direction of the third direction Z to the positive direction is inclined relative to the positive direction of the first direction X from the positive direction of the first direction X to the negative direction of the third direction Z at an angle greater than the above-mentioned predetermined angle of the first electrode tab 310 of the third layer battery 10 (battery element 100).

[0088] As mentioned above, although embodiment of this invention was demonstrated referring drawings, the said embodiment is an example of this invention, Various structures other than the said can also be employ|adopted.

[0089] This application claims the benefit of priority based on Japanese patent application No. 2020-016866, filed on February 4, 2020, the disclosure of which is incorporated herein in its entirety.

[0090] Explanation of symbols

[0091] 10—battery, 100—battery element, 100a—laminate, 110—first electrode, 112—first current collector, 112a—first current collector portion, 114—first active material layer, 120—second electrode, 122—second current collector, 124—second active material layer, 130—separator, 200—exterior material, 202—incision, 210—first exterior material sheet, 220—second exterior material sheet, 310—first pole tab, 320—second pole tab, C—fold, J1—first clamp, J2—second clamp, RG1—first region, RG2—second region, X—first direction, Y—second direction, Z—third direction.

Claims

1. A battery, characterized in that: have: A battery element comprising a stacked portion including a plurality of first electrodes, a plurality of second electrodes, and separators between the plurality of first electrodes and the plurality of second electrodes, and a plurality of first current collector portions extending from the stacked portion; An outer packaging material that wraps the battery element; and a first electrode tab having a base end located on the side where the battery element is located and connected to the plurality of first current collector portions; The plurality of first current collector portions and the outer packaging material have a bent portion bent along a fold, wherein the fold is formed in a portion of the plurality of first current collector portions and the outer packaging material located between the stacked portion and the base end of the first electrode tab. The base end of the first electrode tab and the front end of the outer packaging material bent at the bending portion face the same direction. The plurality of first current collector portions between the stacked portion and the first electrode tab have a first region, in which a thickness of a bundle including the plurality of first current collector portions decreases from the stacked portion to the first electrode tab, and a rate of decrease of the thickness decreases from the stacked portion to the first electrode tab, The folds of the plurality of first current collector portions are located at one of the first regions of the plurality of first current collector portions and a region of the plurality of first current collector portions located on the first tab side with respect to the first region.

2. The battery according to claim 1, characterized in that The above-mentioned multiple first collector parts between the above-mentioned stacking part and the above-mentioned first pole lug have a second region located on the side of the above-mentioned stacking part relative to the above-mentioned first region, and in this second region, the above-mentioned thickness of the above-mentioned bundle including the above-mentioned multiple first collector parts decreases from the above-mentioned stacking part to the above-mentioned first pole lug, and the reduction rate of the above-mentioned thickness increases from the above-mentioned stacking part to the above-mentioned first pole lug.

3. The battery according to claim 1 or 2, characterized in that: A cutout opening in a direction from the stacked portion side toward the first electrode tab side is provided on at least one of both sides of the first electrode tab in the exterior material.

4. The battery according to claim 3, characterized in that In a direction from the first tab side toward the stacked portion side, an edge portion of the cutout on the stacked portion side is located on the first tab side with respect to the first region of the plurality of first current collector portions.

5. The battery according to claim 3, characterized in that The cutout opens in a direction from the first electrode tab toward both sides of the first electrode tab.

6. The battery according to claim 3, characterized in that At least one of both sides of the laminated portion in the exterior material is folded back toward the laminated portion.

7. A battery stack, characterized in that: It has multiple batteries stacked on top of each other. The above-mentioned multiple batteries respectively have: A battery element comprising a stacked portion including a plurality of first electrodes, a plurality of second electrodes, and separators between the plurality of first electrodes and the plurality of second electrodes, and a plurality of first current collector portions extending from the stacked portion; An outer packaging material that wraps the battery element; and a first electrode tab having a base end located on the side where the battery element is located and connected to the plurality of first current collector portions; In each of the plurality of batteries, the plurality of first current collector portions and the outer packaging material have a bent portion bent along a fold, the fold being formed in a portion of the plurality of first current collector portions and the outer packaging material located between the stacked portion and the base end of the first electrode tab, In each of the plurality of batteries, the base end of the first electrode tab and the leading end of the outer packaging material bent at the bent portion face the same direction. The plurality of first tabs of the plurality of batteries are bundled together. In each of the plurality of batteries, the plurality of first current collector portions between the stacked portion and the first tab have a first region, in which a thickness of a bundle including the plurality of first current collector portions decreases from the stacked portion to the first tab, and a rate of decrease in the thickness decreases from the stacked portion to the first tab, In each of the plurality of batteries, the folds of the plurality of first current collector portions are located at one of the first regions of the plurality of first current collector portions and a region of the plurality of first current collector portions located on the first tab side relative to the first region.

8. The battery stack according to claim 7, characterized in that: In each of the above-mentioned multiple batteries, the above-mentioned multiple first collector portions between the above-mentioned stacking portion and the above-mentioned first pole lug have a second region located on the side of the above-mentioned stacking portion relative to the above-mentioned first region, and in this second region, the above-mentioned thickness of the above-mentioned bundle including the above-mentioned multiple first collector portions decreases from the above-mentioned stacking portion to the above-mentioned first pole lug, and the reduction rate of the above-mentioned thickness increases from the above-mentioned stacking portion to the above-mentioned first pole lug.

9. The battery stack according to claim 7 or 8, characterized in that: In each of the plurality of batteries, a cutout opening in a direction from the stacked portion side toward the first electrode tab side is provided in at least one of both sides of the first electrode tab in the exterior material.

10. The battery stack according to claim 9, characterized in that: In each of the plurality of batteries, an edge of the cutout on the stacked portion side is located on the first tab side relative to the first region of the plurality of first current collector portions in a direction from the first tab side toward the stacked portion side.

11. The battery stack according to claim 9, characterized in that: In each of the plurality of batteries, the cutout opens in a direction from the first electrode tab toward both sides of the first electrode tab.

12. The battery stack according to claim 9, characterized in that: In each of the plurality of batteries, at least one of both sides of the stacked portion in the exterior material is folded back toward the stacked portion.

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